1. Field of the Invention
This invention relates to a radiation image recording and reproducing system wherein a radiation image is stored on a stimulable phosphor sheet, read out therefrom, and then reproduced as a visible image. This invention particularly relates to a radiation image recording and reproducing system which receives identification information (ID information) giving specifics about a radiation image from an external apparatus, such as a host computer.
2. Description of the Prior Art
When certain kinds of phosphors are exposed to radiation such as X-rays, .alpha.-rays, .beta.-rays, .gamma.-rays, cathode rays or ultraviolet rays, they store part of the energy of the radiation. Then, when the phosphor which has been exposed to the radiation is exposed to stimulating rays such as visible light, light is emitted by the phosphor in proportion to the amount of energy stored thereon during its exposure to the radiation. A phosphor exhibiting such properties is referred to as a stimulable phosphor.
As disclosed in U.S. Pat. No. 4,258,264 and Japanese Unexamined Patent Publication No. 56(1981)-11395, it has been proposed to use stimulable phosphors in radiation image recording and reproducing systems. Specifically, a sheet provided with a layer of the stimulable phosphor (hereinafter referred to as a stimulable phosphor sheet) is first exposed to radiation which has passed through an object, such as the human body. A radiation image of the object is thereby stored on the stimulable phosphor sheet. The stimulable phosphor sheet is then two-dimensionally scanned with stimulating rays, such as a laser beam, which cause it to emit light in proportion to the amount of energy stored thereon during its exposure to the radiation. The light emitted by the stimulable phosphor sheet, upon stimulation thereof, is photoelectrically detected and converted into an electric image signal. The image signal is then used during the reproduction of the radiation image of the object as a visible image on a recording material such as photographic film, on a display device such as a cathode ray tube (CRT) display device, or the like.
Radiation image recording and reproducing systems which use stimulable phosphor sheets are advantageous over conventional radiography using silver halide photographic materials, in that images can be recorded even when the energy intensity of the radiation to which the stimulable phosphor sheet is exposed varies over a wide range. More specifically, since the amount of light which the stimulable phosphor sheet emits when being stimulated varies over a wide range and is proportional to the amount of energy stored thereon during its exposure to the radiation, it is possible to obtain an image having a desirable density regardless of the energy intensity of the radiation to which the stimulable phosphor sheet was exposed. In order to obtain the desired image density, an appropriate read-out gain is set when the emitted light is being detected and converted into an electric signal to be used in the reproduction of a visible image on a recording material, such as photographic film, or on a display device, such as a CRT display device.
In cases where the radiation image recording and reproducing systems described above are utilized for making diagnoses of human bodies, the radiation dose to human bodies can be kept markedly lower than when conventional X-ray image recording and diagnosing systems are used.
In the radiation image recording and reproducing systems described above, a plurality of radiation images are processed. Therefore, ID information giving specifics about each radiation image, such as the name of the patient recorded, the sex of the patient recorded, the name of the disease of the patient recorded, the diseased part of the patient recorded, and the date on which the image was recorded, is entered into the radiation image recording and reproducing systems. In cases where a plurality of image signals representing the radiation images are stored on a storage means, the ID information is utilized as a data base for retrieving the image signal corresponding to the ID information from the storage means. Alternatively, when a radiation image is reproduced as a visible image, the ID information corresponding to the radiation image is reproduced together with the visible image and utilized in the course of making a diagnosis.
In cases where a radiation image recording and reproducing system is located in, for example, a hospital, it often occurs that the hospital already has its own system, with which the ID information, such as the name of the patient recorded, is stored in a host computer, or the like. In such cases, considerable time and labor are required for operations to be carried out independently for entering the ID information into the host computer, or the like, which has already been located in the hospital, and the radiation image recording and reproducing system which is newly located in the hospital. Therefore, it is desired that the ID information can be entered in the on-line mode from the host computer, or the like, which has already been located in the hospital, into the radiation image recording and reproducing system which is newly located in the hospital. However, the signal format of the ID information stored in a host computer, or the like, has not been standardized, but varies for different hospitals, or the like. Accordingly, when the host computer, or the like, and the radiation image recording and reproducing system are connected to each other, a signal format converting means, such as a signal format converting program, must be designed independently in accordance with the location of the host computer, or the like, and the radiation image recording and reproducing system (e.g. the hospital). In such cases, considerable time, labor, and expense are required for such a signal format converting means to be designed.